This invention relates in general to articulations or like pivot means and has specific reference to a self-contained modular pivot intended for use notably in various mechanisms, especially in robots and the like.
Most hitherto known robots and mechanisms comprise pivot means. However, these pivot means are seldom designed and constructed in the form of self-contained structures, but rather as components that cannot be separated from an assembly.
This technique is objectionable as it has several inconveniences, the main ones being:
THE FACT THAT THE MECHANISM OR ROBOT UTILIZING SUCH PIVOT MEANS IS A PERMANENT STRUCTURE SO THAT IT IS APPLICABLE ONLY IN WELL-DEFINED CASES. If it is contemplated to extend its possible uses, it will readily occur that the only solution consists in constructing another robot, generally completely different from the initial one, so that the same problem arises each time;
THE FACT THAT THE PIVOT OR PIVOTS DESIGNED FOR A SPECIFIC APPLICATION ARE WELL-ADAPTED, OR SUPPOSED TO BE WELL-ADAPTED, FOR THE MECHANISM ON WHICH THEY ARE MOUNTED. This does not ensure that their cost and over-all dimensions have been minimized;
THE FACT THAT A PIVOT INCORPORATED IN A GIVEN MEMBER IS HARDLY LIKELY TO EVOLVE FROM A PURELY TECHNICAL POINT OF VIEW. Indeed, except in case of faulty operation, this pivot is preserved as such throughout the useful like of the product on which it is mounted. Therefore, it will behave in a quite ordinary way and its performance will be behind the actual and present technological possibilities and trends.
It is the essential object of the present invention to avoid these inconveniences by providing a self-contained modular pivot. Nowadays, new techniques are provided to separate a device into its elementary functions, each thus isolated function leading to a modular construction having minimum over-all dimensions and the best possible technological efficiency of performance, each module being coupled, linked or connected to another module performing the same function or a different function, through standard means, or variable dimensions, whereby economical and standardized structures well adapted for each purpose can be obtained.
Each separate function may on the other hand be performed by several modules of different sizes, each module having a predetermined capacity, whereby a wide range of requirements can be met by using a relatively small number of component elements.
In addition, by preserving (in most cases without difficulty) standard over-all dimensions and coupling means for connecting the standard modules to other standard modules, it is clear that each module can evolve with the technology while remaining constantly interchangeable with the preceding module.
According to this invention, the self-contained pivot means for interconnecting or coupling two machine elements adapted to perform any desired rotational movement in relation to each other about an axis of rotation comprises a first flange or plate secured to the first machine element, said first flange having centered and locked in relation thereto the internally toothed annulus of a reduction gear rigid with a tubular member concentric thereto; a pair of rolling-contact bearings secured the one between said internally toothed annulus and said first flange, the other to the opposite end of said tubular member, said rolling-contact bearings are centered through their inner races and have their play adjustable by means of an adjustment device rigid with said tubular member, the outer race of said rolling-contact bearings is adapted to center and lock in the axial direction a second tubular member rotatably rigid with the other machine element, said second tubular member is closed at its end opposite said first flange by a second flange to which the motor driving said pivot and said reduction gear meshing with the internally toothed annulus secured to said first flange are fastened.
According to a first feature of this invention, the reduction gear is of the so-called "distortion-wave harmonic drive" type.
According to another characteristic feature of this invention the self-contained pivot incorporates all the necessary mechanical components, including the power control and the position coder for measuring the relative angular position of the two machine elements.
Other features of this invention will appear as the following description proceeds.